Abrasive wheel



Jan. 7, 1958 6.0; LEGGETT ABRASIVE WHEEL Fi'i'ed April 18, 1955 cur 0.LEGGETT; INVENTOR.

Unite States Patent Products, Inc., Culver City, 'Calif., .a corporationof California Application April F118, 1955, Serial No. 501,908

3 Claims. oust-195.5

This invention "relates to abrasive wheels of the type utilizing aplurality of abasive coated flexible leaves anchored at their inneredges to a tubular hub and radiatin'g therefrom in circumfereritiallyspaced annular array. The general object of the invention is to providesuch an abrasive Wheel of "improved sturdiuess and durability.

Specifically, the invention contemplates an abrasive wheel wherein theabrasive coated leaves are anchored to an anchor sleeve of perforatedsheet material which may be, and preferably is, of -sheet-metal, with 'ahigh degree of tensile strength and fairly rigid, and W'hereinthe leavesare attached thereto by an annular film of bonding material portions ofwhich project into or "through the perforations in the anchor sleeve andother portions "of which project around the inner edges of the leavesand into the crevices between the leaves "at said inner edges, so as to:provide an exceedingly sturdy bond between the sleeve and the inneredges of the leaves.

@ther objects "will become apparent in "the ensuing specifications andappended drawing in which:

Fig. 1 is a side view of an abrasive wheel embodying the invention;

Fig. '2 is a sectional view thereof, "taken through the axis of wheel,as indicated by line 2- 2 'of Fig. '1;

Fig. 3 is a fragmentary enlarged detail sectional view showing the jointbetween the ends of the strip composing the anchor sleeve;

Fig. 4 is a fragmentary detail view looking at the inside of the anchorsleeve, at the joint therein;

, Eig. .5 .is .a fragmentary enlarged detail sectional view taken online :55 of Fig. 1;

Fig. "6 is a fragmentary enlarged detail sectional view taken on line 66of Fig. 1;

Figs. 7 and 8 are fragmentary details of an end of the anchor strip, inintermediate stages of fabrication.

Referring now to the drawings in detail, I have shown therein, as anexample of one form in which the invention may be embodied, an abrasivewheel comprising a plurality of rectangular leaves 10 of flexible sheetmaterial, such as cloth fabric, kraft paper or sheet plastic, eachhaving one face coated with abrasive grains 11 secured by a suitablecement, in accordance with Well known practice in the production ofsandpaper, emery cloth, etc. Leaves 10 are anchored at their inner endsin a hub assembly comprising an anchor sleeve 12 and a pair of facebinding rings 13, and project therefrom in radial planes with referenceto the axis of rotation of the wheel, with which the sleeve 12 and ringsare coaxial. The inner edges of the leaves 10 are parallel to the axisof rotation and are uniformly spaced about the circumference of anchorsleeve 12, to provide an annular array of abrasive leaves in which theabrasive coatings all face in a common circumferential direction. Thecoating 11 of each leaf 10 is directly adjacent the uncoated back faceof an adjoining leaf 10.

Anchor sleeve 12 and face binding rings 13 are of perforated stifi?sheet material such as sheet metal, having a large number of smallperforations 14 and 15 respecice tively. A cylindrical film loot cementis attached to'the inner surface of anchor sleeve 12, portions 17"thereof projecting through perforations '14 to securely anchorth'efil'm to the sleeve. Annular films 18 of cement are attached to theinner faces of binding rings 13, portions 19 thereofproj'e'ctingthroughperforations 15. The inner edges of leaves 10 are embedded in film 16and the 'respective side edges -thereof are "embedded in side films 18.The grip of films 16 and 18 against the respective edges of the leaves10 is adequate to anchor the leaves against the pull of centrifugalforce when the "wheel is rotating at high speed, and to resist thecircumferential drag imposed on the leaves by .a surface being ground orbuifed.

The rings 13 are of angle section, each being provided with acylindrical pilot flange 20 extending axially from its inner margin intoa respective end of a hub sleeve 21 which is disposed as a liner withinanchor sleeve 12. This piloting telescoping of flanges 20 into 'hubsleeve 21 establishes an accurately coaxial relation between bindingrings 13, anchor ring 12 and the annular array of abrasive coated leaves10. This is extremely important in order to avoid destructive "unbalancein the rotating Wheel.

Anchor sleeve 12 is initially formed as a straight strip of perforatedribbon stock, with end portions cornernotched 'to provide narrowedtongues 23 '(Fig. 7) which are "bent at right angles as :shown at '23 inFig. 8, for insertion in a slot 24 in hub sleeve 21. When the benttongues 23' of both ends of the strip have been inserted in slot 2%,they are spread apart, bent circumferentially away from one another at23", and flattened against the inner face of hub sleeve 21, thus lockingthe anchor sleeve to the "hub sleeve. The hub sleeve 21 iscircumferentially continuous .past the ends of slot 2'4. it may befabricated as a short -section of seamless tubing, with theslot'24lanced therein, or .it maybe fabricated'tro'm a strip of ribbon stock,its ends notched to provide respective halves of slot 2 3, and leavingprojecting tabs which are butt welded at 25 after coiling the strip intoa ring.

The'w heel is fabricated and assembled, using my improved imeth'odwherein the hub ring '21 is fabricated as one unit, and "the anchorstrip 12"., with leaves attached thereto at their inner edges, isfabricated :as :-'a separate unit which is then attached to the hub:sleeve. The leaves 10, cut to uniform length from a roll of abrasivecoated ribbon, are stacked on the fiat anchor strip 12, previouslycoated with cement and supported on a horizontal surface, and the weightof the leaves causes their lower edges to sink into the cement film onthe anchor strip. The leaves are held in upstanding positions, withtheir side edges accurately aligned, by a suitable assembly jig. Theyare allowed to remain supported in the jig until the cement hasthoroughly hardened around their lower edges. The assembly of leaves andanchor strip is then coiled around the hub sleeve 21, and is stretchedaround the hub sleeve to bring the tongues 23 into registry with slot24. The tongues are then inserted into the slot 24, are grasped frominside the hub sleeve, and are pulled tight to complete the operation ofwrapping the anchor sleeve snugly against the hub sleeve. The tongues 23are then spread to become the clincher tongues 23.

The rings 13, after being coated with cement, are then inserted into therespective ends of the hub sleeve and secured by the adhesive attachmentto leaves 10.

Since the anchor sleeve 12 is formed of fairly rigid sheet materialhaving a high degree of tensile strength, the hub ring 21 may beomitted, if desired.

I claim:

1. In an abrasive Wheel: a plurality of abrasive coated leaves arrangedwith their inner edges parallel to a com- J mon axis of rotation of saidwheel and uniformly spaced circumferentially in a closed cylindricalarray encircling and coaxial with said axis; an anchor sleeve of sheetmaterial having a largenumber of small perforations peripherallyconforming to said cylindrical array encircled by said inner edges; acylindrical film of bonding medium having portions thereof projectinginto said perforations and having other portions extending past saidinner edges and into spaces between adjoining leaves; and flat facebinding rings engaging the respective side edges of said leaves andjoined to said anchor sleeve at their inner margins.

2. An abrasive wheel as defined in claim 1, wherein said face bindingrings are of sheet material having a large number of small perforationstherein; and including side films of bonding material including portionsthereof extending into the perforations of said side binding rings andother portions thereof extending into the spaces between adjacent leavesalong the side edges thereof. 1

3. An abrasve wheel as defined in claim 2, including anendlesscylindrical hub sleeve fitted within said anchor sleeve andhaving a-transverse slot, closed at both ends; said anchor sleeve havingcircumferentially terminal portions projecting radially inwardly throughsaid slot, spread apart circumferentially, and engaging the inner faceof said hub sleeve to securely lock said terminal portions to the hubsleeve.

4. An abrasive Wheelas defined in claim 3, wherein said face bindingrings are of angle section, each including a cylindrical pilot flangesnugly telescoped within a respective end portion of said hub sleeve.

5. An abrasive wheel as defined in claim 1, including an endlesscylindrical hub sleeve fitted within and secured to said anchor sleeve,and wherein said face binding rings are of angle section, each includinga cylindrical pilot flange snugly telescoped within a respective endportion of said hub sleeve.

6. In an abrasive wheel: a plurality of abrasive coated leaves arrangedwith their inner edges parallel to a common axis of rotation of saidwheel and uniformly spaced circumferentially in a closed cylindricalarray encircling and coaxial with said axis; an anchor sleeve of sheetmaterial having a large number of small perforations peripherallyconforming to said cylindrical array encircled by said inner edges; acylindrical film of bonding medium having portions thereof projectinginto said perforations and having other portions extending past saidinner edges and into spaces between adjoining leaves; and flat facebinding rings engaging the respective side edges of said leaves andjoined to said anchor sleeve at their inner margins; an endlesscylindrical hub sleeve fitted within said anchor sleeve and having atransverse slot, closed at both ends; said anchor sleeve havingcircumferentially terminal portions projecting radially inwardly throughsaid slot, spread apart circumferentially, and engaging the inner faceof said hub sleeve to securely lock said terminal portions to the hubsleeve; said face binding rings being of angle section, each including acylindrical pilot flange snugly telescoped within a respective endportion of said hub sleeve, extending substantially to the ends of saidslot, and secured to said hub sleeve to reinforce the portions thereoflying outwardly of said slot ends.

7. An abrasive wheel as defined in claim 6, wherein said face bindingrings are of sheet material having a large number of small perforationstherein; and including side films of bonding material including portionsthereof extending into the perforations ofsaid side bind-, ing rings andother portions thereof extending into the spaces between adjacent leavesalong the side edges thereof.

8. In an abrasive wheel: a plurality of abrasive coated leaves arrangedwith their inner edges parallel to a common axis of rotation of saidwheel and uniformly spaced circumferentially in a closed cylindricalarray encircling and coaxial with said axis; an anchor sleeve of sheetmaterial having a large number of small perforations peripherallyconforming to said cylindrical array encircled by said inner edges; acylindrical film of bonding medium having portions thereof projectinginto said perforations and having other portions extending past saidinner edges and into spaces between adjoining leaves; an endlesscylindrical hub sleeve fitted within said anchor sleeve and having atransverse slot, closed at both ends; said anchor sleeve havingcircumferentially terminal portions projecting radially inwardly throughsaid slot, spread apart circumferentially, and engaging the inner faceof said hub sleeve to securely lock said terminal portions to the hubsleeve.

References Cited in the file of this patent UNITED STATES PATENTS1,230,518 Robinson June, 19, 1917 2,164,800 Davis July 4, 1939 2,678,523Leggett May 18, 1954

